Python异常信息的输出

捕获异常时，有 2 种方式可获得更多的异常信息，分别是：

• 使用 sys 模块中的 exc_info 方法；
• 使用 traceback 模块中的相关函数。

Python异常信息的输出exc_info方法

下面看一下输出异常信息的示例

# 定义除法函数
def divi(x,y):
    try:
        if x>y:
            z=x/y
            return z
    except Exception as e:
        print(e)

res=divi(6,2)
print(res)
res=divi(6,0)
print(res)
res=divi(6,"2")
print(res)

运行结果

C:UsershccmaAnaconda3python.exe E:/wkp01/p00/test01/atestpkg/t32.py
3.0
division by zero
None
'>' not supported between instances of 'int' and 'str'
None

Process finished with exit code 0

上面程序，异常信息输出内容不完整。使用exc_info方法输出较完整信息，代码如下。

import sys

# 定义除法函数
def divi(x,y):
    try:
        if x>y:
            z=x/y
            return z
    except Exception as e:
        print(sys.exc_info())

res=divi(6,2)
print(res)
res=divi(6,0)
print(res)
res=divi(6,"2")
print(res)

运行结果（异常信息较完整）

C:UsershccmaAnaconda3python.exe E:/wkp01/p00/test01/atestpkg/t32.py
3.0
(<class 'ZeroDivisionError'>, ZeroDivisionError('division by zero'), <traceback object at 0x0000023DE5814DC8>)
None
(<class 'TypeError'>, TypeError("'>' not supported between instances of 'int' and 'str'"), <traceback object at 0x0000023DE582BAC8>)
None

Process finished with exit code 0

Python异常信息的输出traceback 方法

import traceback

# 定义除法函数
def divi(x,y):
    try:
        if x>y:
            z=x/y
            return z
    except Exception as e:
        print(traceback.format_exc())

res=divi(6,2)
print(res)
res=divi(6,0)
print(res)
res=divi(6,"2")
print(res)

运行结果（有异常信息和出错位置的追踪）

C:UsershccmaAnaconda3python.exe E:/wkp01/p00/test01/atestpkg/t32.py
3.0
Traceback (most recent call last):
  File "E:/wkp01/p00/test01/atestpkg/t32.py", line 7, in divi
    z=x/y
ZeroDivisionError: division by zero

None
Traceback (most recent call last):
  File "E:/wkp01/p00/test01/atestpkg/t32.py", line 6, in divi
    if x>y:
TypeError: '>' not supported between instances of 'int' and 'str'

None

Process finished with exit code 0

Python将异常信息输出到文件

traceback模块中的函数还可以将Python将异常信息输出到文件，示例代码如下。

import traceback

# 定义除法函数
def divi(x,y):
    try:
        if x>y:
            z=x/y
            return z
    except Exception as e:
        print(traceback.print_exc(file=open("log.txt","a")))

res=divi(6,2)
print(res)
res=divi(6,0)
print(res)
res=divi(6,"2")
print(res)

运行结果

C:UsershccmaAnaconda3python.exe E:/wkp01/p00/test01/atestpkg/t32.py
3.0
None
None
None
None

Process finished with exit code 0

另外，生成的log.txt文件，内容如下。

Traceback (most recent call last):
  File "E:/wkp01/p00/test01/atestpkg/t32.py", line 7, in divi
    z=x/y
ZeroDivisionError: division by zero
Traceback (most recent call last):
  File "E:/wkp01/p00/test01/atestpkg/t32.py", line 6, in divi
    if x>y:
TypeError: '>' not supported between instances of 'int' and 'str'